Th17 cell and inflammatory cytokine (IL-17A, IL-17F, etc.) produced thereby cause a decrease in QOL as a severe etiology cell and factor accompanying enhancement of a systemic new immune response, in various autoimmune disease such as inflammatory bowel disease (IBD), rheumatoid arthritis, multiple sclerosis or psoriasis. However, the existing therapeutic drugs show only limited effects, and therefore, the earliest possible development of a novel therapeutic drug has been desired.
Involvement of T cells, inter alia, Th17 cell and inflammatory cytokines (IL-17A, IL-17F, etc.) produced thereby, in the pathology of these immune disease has been drawing attention in recent years.
Moreover, it has been recently clarified that a Retinoid-related Orphan Receptor (ROR) γt, which is one of the orphan nuclear receptors, plays an important role in the differentiation of Th17 cells and production of IL-17A/IL-17F. That is, it has been reported that RORγt is mainly expressed in Th17 cells and functions as a transcription factor of IL-17A and IL-17F, as well as a master regulator of Th17 cell differentiation.
Therefore, a medicament that inhibits the action of RORγt is expected to show a treatment effect on various immune disease by suppressing differentiation and activation of Th17 cells.
Non-Patent Document 1 discloses the following compound as an amide compound.

Patent Document 1 discloses a compound represented by the formula:
which is a compound having a Xa factor inhibitory action, and is useful for the treatment of thromboembolism.
Patent Document 2 discloses a compound represented by the general formula:
whereinE and F are independently a saturated or unsaturated non-cyclic hydrocarbon group having 1, 2, 3, 4 or 5 carbon atoms;X and Y are independently methylene or the like;R8 is hydrogen or the like; andA and B are the same or different and each is selected from
                wherein R1, R2 and R3 are the same or different and each is selected from hydrogen, halogen, an alkyl group having 1 to 5 carbon atoms, and the like,which is a melanocortin receptor agonist or antagonist, and is useful for the treatment of inflammation and the like.        
Patent Document 3 discloses a compound represented by the formula:
whereinM* is (CH2)n, (n=0, 1 or 2);P* is C═O, CONH, CO2, —CH2— or the like;A* is carbonyl (C═O) or the like;R is selected from H, alkyl (C1-C4) and the like;R1 is selected from H, alkyl (C1-C4) and the like;R2 is selected from H, alkyl (C1-C4) and the like;W is selected from (alpha-aminoacyl)amide, aminoalkyl, amino and the like; andX is selected from aryl (C6-C10), mono-substituted aryl (C6-C10) and the like,which is an efflux pump inhibitor, and is useful for the treatment of bacterial infection.
Patent Document 4 discloses, as a fused heterocyclic compound, a compound represented by the formula:
whereinR1A is an optionally substituted hydrocarbon group or an optionally substituted hydrocarbon-oxy group,R2A and R3A are each independently a hydrogen atom, an optionally substituted hydrocarbon group or the like, orR2A and R3A in combination optionally form, together with the carbon atoms which they are bonded to, an optionally substituted hydrocarbon ring,R5A is a hydrogen atom or a halogen atom,Q′ is
                wherein        [A1] are the same or different and each is a methylene group optionally substituted by C1-6 alkyl group(s) optionally substituted by hydroxy group(s) and the like, wherein the two substituents bonded to the single carbon atom are optionally combined to each other to form a hydrocarbon ring, and        n is an integer of 1 to 5, or the like, andRing B′ is a benzene ring optionally further having substituent(s), or the like,which has a RORγt inhibitory action, and is useful for the treatment of inflammatory bowel disease (IBD) and the like.        
Patent Document 5 discloses a compound represented by the formula:
whereinA1 is CRA1 wherein e is a hydrogen atom or a substituent, or a nitrogen atom,A2 is CRA2 wherein RA2 is a hydrogen atom or a substituent, or a nitrogen atom,A3 is CRA3 wherein RA3 is a hydrogen atom or a substituent, or a nitrogen atom, or,provided that when A2 is CRA2 wherein RA2 is a substituent, andA3 is CRA3 wherein RA3 is a substituent, then RA2 and RA3 in combination optionally form, together with the carbon atoms which they are bonded to, a carbocycle or a heterocycle,R1 is an optionally substituted carbocyclic group or the like,R2 is a hydrogen atom or a substituent,one of R3 or R4 is an optionally substituted carbocyclic group, an optionally substituted aromatic nitrogen-containing heterocyclic group or an optionally substituted fused non-aromatic heterocyclic group, and the other is a hydrogen atom or a substituent,R5 is a hydrogen atom or a substituent, andR9 is a hydrogen atom or a hydroxy group, provided that when R9 is a hydroxy group, then A1, A2 and A3 are CRA1, CRA2 and CRA3, respectively.
Patent Document 6 discloses a compound represented by the formula:
whereinX is carbon or nitrogen,R1 is —CF2Ra, wherein Ra is H, F or C1-6 alkyl,R2 is H, halo, CF3, a C1-6 alkyl or C1-3 alkoxy,R3 is a chemical moiety selected from the group consisting of C3-6 cycloalkyl, 5- to 6-membered heterocycle, 5- to 6-membered heteroaryl and phenyl, wherein the heterocycle and heteroaryl each independently contains 1 to 3 heteroatoms selected from N, O and S, and the moiety is each independently optionally substituted by 1 to 3 substituents selected from halo, C1-6 alkyl, C1-6 alkoxy, CF3 and cyano,R4 is H or C1-6 alkyl, andR5 is a chemical moiety selected from the group consisting of 5- to 6-membered heteroaryl and quinolinyl, wherein the heteroaryl each independently contains 1 to 3 heteroatoms selected from N, O and S, and the moiety is each independently optionally substituted by 1 to 3 of R6 substituents selected from C1-6 alkyl, CF3, cyano, C1-6 alkoxy, halo, amino, C1-3 alkylamino, di-C1-3 alkylamino, —CH2P(O)(OR7)(OR8), —C(O)OR7, —CH2C(O)OR7 and aryl C1-6 alkyl, and R7 and R8 are each independently H or C1-6 alkyl, and the aryl of the arylalkyl is each independently optionally substituted by 1 to 3 substituents selected from C1-6 alkyl, CF3, cyano, C1-6 alkoxy, halo, carboxy, amino, C1-3 alkylamino and di-C1-3 alkylamino, which is useful for the treatment of glucokinase activation-related diseases.
Non-Patent Document 2 discloses the following compound.

Patent Document 7 discloses a compound represented by the formula:
wherein each symbol is as defined in the document,which is useful for the treatment or prophylaxis of cancer, cell signaling pathway-related diseases and microorganism infection-related diseases.
Patent Document 8 discloses a compound represented by the formula:
whereinQ is a group represented by —C(-R11)=C(-R12)-SO2— wherein R11 and R12 are bonded to each other to form a 5- to 7-membered ring together with —C═C—, or each independently a hydrogen atom or a substituent,R1 is a substituent,R2 is a substituent,m is an integer of 0 to 5, when m is 2 or more, then plural R2 are the same or different, or they are optionally bonded to each other to form a ring, andX is a group capable of being leaved by coupling reaction with an oxidized product of a developing agent.
Patent Document 9 discloses a compound represented by the formula:
whereinR1, R2, R3 and R4 are independently selected from hydrogen; C1-8 alkyl; 3- to 8-membered monocyclic or bicyclic cycloalkyl; 3- to 8-membered monocyclic or bicyclic heterocycle wherein one, two or three carbon atoms are replaced by heteroatom(s) selected from oxygen, nitrogen and sulfur; 6- to 10-membered monocyclic or bicyclic aryl; or 5- to 10-membered monocyclic or bicyclic heteroaryl wherein one, two, three or four carbon atoms are optionally replaced by nitrogen, oxygen or sulfur; the all of groups are optionally unsubstituted or substituted by 1 or plural substituents;X is —N— or —O—;R5 is —H or —F;R6 is —H or —CH3; orwhen X is —N—, and R3 and R4 in combination form a 4- to 6-membered heterocycle together with the nitrogen atom they are bonded to, then one additional carbon atom may be replaced by nitrogen, oxygen or sulfur,which is useful for the treatment of cancer.
The following compounds are registered Chemical Abstracts.
